by Jackie Kucinich and Gregory Korte, USA TODAY

by Jackie Kucinich and Gregory Korte, USA TODAY

WASHINGTON -- New polling numbers released Tuesday show Mitt Romney's debate bounce has brought him even, or in some cases, carried him past President Obama â?? shifts that reiterated what has been the one constant through the 2012 election: The race is one of the closest in history.

For the first time since last October - when a head-to-head Romney-Obama matchup was just a hypothetical - Romney is leading Obama in the RealClear Politics average of national polls. The advantage: a slim 0.7 percentage points.

Both the Obama and Romney campaigns said they expected the polls to shift and the race to tighten in the final weeks before Election Day but pointed to their respective party's enthusiasm as proof their candidate had the upper hand.

"I know that a week ago; when polls were showing a different result, we were being questioned about the state of the race," Romney senior adviser Eric Fehrnstrom told NBC News. "Our advice was to simply caution everybody to be patient, that there's going to be a lot of ups and downs in this campaign, but it's going to be tight right up until the end."

Obama campaign spokeswoman Jen Psaki told reporters, "We're going to run like we're five points down, no matter what the polls say."

Romney's improvement in the polls has as much to do with changes in methodology as news events. As the campaign enters the final month, Gallup's daily tracking poll switches from counting registered voters to those most likely to show up on or before Election Day, based on a seven-question screen Gallup has used, in some version, since 1952.

Among those likely voters, Romney leads 49% to 46%, with a margin of error of +/- 2 percentage points, Gallup says.

Republicans always have a cultural advantage in likely voters, said Gallup pollster Frank Newport. "That's why we say rain is the Republican's best friend," because it is more likely to keep Democratic voters away on Election Day. Looking at registered voters, the fundamentals of the race haven't changed much from a week ago: It was close before, and it's close now.

"There was definitely momentum or gains by Romney coming out of the debate, and the question now is whether it lasts or dissipates," Newport said. "It's a little early to know definitively. We need a few more days."

"The upward trend is always a good sign for Gov. Romney," said Republican National Committee Political Director Rick Wiley.

Wiley said while the daily tracking polls tend to be "all over the place," the current set showed Americans liked what they saw during Wednesday night's debate.

"Following his decisive debate win last week," Wiley said in an e-mail, "the American people saw a man who is ready to become president on Day One, and the polling shows that."

The polls that matter most are in battleground states with electoral votes up for grabs, and a CNN/ORC International poll showed the race tightening in the critical battleground of Ohio. Obama still leads Romney 51% to 47% among likely voters in the poll, conducted Oct. 5-8 and released Tuesday -- but it's now within the margin of error. Prior to the debate, polls showed Obama leading Romney by seven to 10 points in the Buckeye State.

Ohio isn't the only state where the race is tightening.

A recent poll in Michigan showed Obama led Romney 48% to 45%, to the poll of 600 likely voters conducted by EPIC-MRA, a far cry from the president's previous lead of 10 points. Obama held a 49%-46% lead in a Fox News 2 Detroit poll published Tuesday that was conducted two days after his dismal performance in the first debate.

Saul Anuzis, a former Michigan GOP chairman, said the race would be close until Nov. 6 and said the positive polling in swing states "play into the narrative that's important to activists and volunteers."

"The first debate has energized the base and our ground game is breaking records daily, not only in Michigan but in other battleground states," he said.

The University of Cincinnati's Eric Rademacher, co-director of the Ohio Poll, said the Buckeye state is still close - as evidenced by the continued candidate visits there.

"Ohio is closely divided along partisan lines. Both campaigns understand that a strong turnout push - both by absentee ballot and at the polls on Election Day - could tip Ohio's electoral votes in their favor," he said.

To that end, Obama has been touring Ohio's universities in the past month, hitting Kent State, Bowling Green, Cleveland State and - Tuesday afternoon - the Ohio State University campus in Columbus.

Tuesday was the last day to register to vote in Ohio.

Romney, meanwhile, went into heavily Democratic northeast Ohio this week, appearing with New Jersey Gov. Chris Christie in Cuyahoga Falls on Tuesday.

"The Romney campaign is testing whether its current momentum might help diminish the president's margin of victory in that Democratic stronghold," Rademacher said. Romney will visit more GOP-friendly towns Wednesdayon a bus tour of central and western Ohio.

When asked whether Romney would move more resources to Michigan and Pennsylvania as a result of the narrowing polls, Romney political director Rich Beeson said: "I don't want to pull back the curtain on what our strategy would be, but it looks like the Obama campaign has even more real estate to defend than they did a week ago."